Air-intake duct systems for combustion engines, exhaust gas recirculation valves, exhaust gas coolers, exhaust gas feeding devices, and throttle valves and their function are generally known and are described in a large number of patent applications. In recent years attempts have been made to better match the individual parts of a total intake system and exhaust gas recirculation system and to make available complete units from one source in the smallest possible installation space.
A corresponding system is described, for example, in the not yet published patent application with the file number 102 28 247. In this document, the intake pipe taught is connected via a distributor plate to an exhaust gas cooler, an exhaust gas feeding device, an exhaust gas recirculation valve, and a throttle valve, so that a compact unit is formed. In the production of such an air-intake duct system, however, all the individual parts must still be connected together via flanges and each individual part must be produced with a stand-alone housing. Thus, the exhaust gas recirculation valve features a duct-forming housing and the throttle valve device features a duct-forming throttle valve connector that is connected only to the distributor plate of the system. Accordingly, this air-intake duct system has a relatively high weight and many assembly steps are needed to connect the individual parts. Moreover, there is no integration of all the known devices to reduce pollutants or fuel consumption.
In the not yet published patent application with the file number 103 21 533, an air-intake duct system is disclosed in which an exhaust gas cooler is integrated into the exhaust gas recirculation duct, which is embodied in one piece with the intake pipe housing. Although such an embodiment reduces the number of production steps, it has the disadvantage that the exhaust gas is conducted through the cooler in each operating state of the combustion engine and an integration of further components is not provided.
Based on these documents, it is the object of the invention to present an air-intake duct system that features pre-mounted units matched to one another, which can be integrated into one another. Moreover, compared to known air-intake duct systems, assembly and production steps are to be saved and a further cost reduction, as well as a weight reduction, are to be achieved. An integration of additional components to reduce pollutants and fuel consumption is to be implemented. The air-intake duct system is to be embodied such that the attachments can be used for different engines, so that production and development costs can be reduced through a modular construction.